| Message ID | 1364847069-2887-3-git-send-email-nzimmer@sgi.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Monday, April 01, 2013 03:11:09 PM Nathan Zimmer wrote: > This eliminates the rest of the contention found in __cpufreq_cpu_get. > I am not seeing a way to use the rcu so we will have to make due with a > rwlock for now. > > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> I've already applied this one. Can you please check if the version in my tree is OK? Rafael > --- > drivers/cpufreq/cpufreq.c | 38 +++++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 19 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 5139eab..7438c34 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -42,7 +42,7 @@ > static struct cpufreq_driver __rcu *cpufreq_driver; > static DEFINE_SPINLOCK(cpufreq_driver_lock); > > -static DEFINE_SPINLOCK(cpufreq_data_lock); > +static DEFINE_RWLOCK(cpufreq_data_lock); > static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); > #ifdef CONFIG_HOTPLUG_CPU > /* This one keeps track of the previously set governor of a removed CPU */ > @@ -150,7 +150,7 @@ static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) > goto err_out_unlock; > > /* get the CPU */ > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + read_lock_irqsave(&cpufreq_data_lock, flags); > data = per_cpu(cpufreq_cpu_data, cpu); > > if (!data) > @@ -159,13 +159,13 @@ static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) > if (!sysfs && !kobject_get(&data->kobj)) > goto err_out_put_module; > > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + read_unlock_irqrestore(&cpufreq_data_lock, flags); > rcu_read_unlock(); > return data; > > err_out_put_module: > module_put(driver->owner); > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + read_unlock_irqrestore(&cpufreq_data_lock, flags); > err_out_unlock: > rcu_read_unlock(); > err_out: > @@ -276,9 +276,9 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) > pr_debug("notification %u of frequency transition to %u kHz\n", > state, freqs->new); > > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + read_lock_irqsave(&cpufreq_data_lock, flags); > policy = per_cpu(cpufreq_cpu_data, freqs->cpu); > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + read_unlock_irqrestore(&cpufreq_data_lock, flags); > > switch (state) { > > @@ -802,12 +802,12 @@ static int cpufreq_add_dev_interface(unsigned int cpu, > } > rcu_read_unlock(); > > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + write_lock_irqsave(&cpufreq_data_lock, flags); > for_each_cpu(j, policy->cpus) { > per_cpu(cpufreq_cpu_data, j) = policy; > per_cpu(cpufreq_policy_cpu, j) = policy->cpu; > } > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + write_unlock_irqrestore(&cpufreq_data_lock, flags); > > ret = cpufreq_add_dev_symlink(cpu, policy); > if (ret) > @@ -858,12 +858,12 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, > > lock_policy_rwsem_write(sibling); > > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + write_lock_irqsave(&cpufreq_data_lock, flags); > > cpumask_set_cpu(cpu, policy->cpus); > per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; > per_cpu(cpufreq_cpu_data, cpu) = policy; > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + write_unlock_irqrestore(&cpufreq_data_lock, flags); > > unlock_policy_rwsem_write(sibling); > > @@ -918,15 +918,15 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) > > #ifdef CONFIG_HOTPLUG_CPU > /* Check if this cpu was hot-unplugged earlier and has siblings */ > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + read_lock_irqsave(&cpufreq_data_lock, flags); > for_each_online_cpu(sibling) { > struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); > if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + read_unlock_irqrestore(&cpufreq_data_lock, flags); > return cpufreq_add_policy_cpu(cpu, sibling, dev); > } > } > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + read_unlock_irqrestore(&cpufreq_data_lock, flags); > #endif > #endif > > @@ -1006,10 +1006,10 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) > return 0; > > err_out_unregister: > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + write_lock_irqsave(&cpufreq_data_lock, flags); > for_each_cpu(j, policy->cpus) > per_cpu(cpufreq_cpu_data, j) = NULL; > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + write_unlock_irqrestore(&cpufreq_data_lock, flags); > > kobject_put(&policy->kobj); > wait_for_completion(&policy->kobj_unregister); > @@ -1067,12 +1067,12 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif > > pr_debug("%s: unregistering CPU %u\n", __func__, cpu); > > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + write_lock_irqsave(&cpufreq_data_lock, flags); > > data = per_cpu(cpufreq_cpu_data, cpu); > per_cpu(cpufreq_cpu_data, cpu) = NULL; > > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + write_unlock_irqrestore(&cpufreq_data_lock, flags); > > if (!data) { > pr_debug("%s: No cpu_data found\n", __func__); > @@ -1111,9 +1111,9 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif > WARN_ON(lock_policy_rwsem_write(cpu)); > cpumask_set_cpu(cpu, data->cpus); > > - spin_lock_irqsave(&cpufreq_data_lock, flags); > + write_lock_irqsave(&cpufreq_data_lock, flags); > per_cpu(cpufreq_cpu_data, cpu) = data; > - spin_unlock_irqrestore(&cpufreq_data_lock, flags); > + write_unlock_irqrestore(&cpufreq_data_lock, flags); > > unlock_policy_rwsem_write(cpu); > >
On Mon, Apr 01, 2013 at 10:41:27PM +0200, Rafael J. Wysocki wrote: > On Monday, April 01, 2013 03:11:09 PM Nathan Zimmer wrote: > > This eliminates the rest of the contention found in __cpufreq_cpu_get. > > I am not seeing a way to use the rcu so we will have to make due with a > > rwlock for now. > > > > Cc: Viresh Kumar <viresh.kumar@linaro.org> > > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > > Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> > > I've already applied this one. > > Can you please check if the version in my tree is OK? > > Rafael > Nope, the previous version was too different, probably best to just replace it. > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2 April 2013 06:26, Nathan Zimmer <nzimmer@sgi.com> wrote: > On Mon, Apr 01, 2013 at 10:41:27PM +0200, Rafael J. Wysocki wrote: >> On Monday, April 01, 2013 03:11:09 PM Nathan Zimmer wrote: >> > This eliminates the rest of the contention found in __cpufreq_cpu_get. >> > I am not seeing a way to use the rcu so we will have to make due with a >> > rwlock for now. >> > >> > Cc: Viresh Kumar <viresh.kumar@linaro.org> >> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> >> > Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> >> >> I've already applied this one. >> >> Can you please check if the version in my tree is OK? >> >> Rafael >> > > Nope, the previous version was too different, probably best to just replace it. Nathan, First of all I should accept that I didn't had your last patch while reviewing this one earlier. Thanks Rafael. Now, I believe the previous patch which Rafael has pushed was good and we can simply keep it. What you can do is, just add a patch over it (which would mostly be 1/2 of your patchset), that simply separates rcu stuff out of the lock and leave lock for cpufreq_data.. -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday, April 02, 2013 10:34:21 AM Viresh Kumar wrote: > On 2 April 2013 06:26, Nathan Zimmer <nzimmer@sgi.com> wrote: > > On Mon, Apr 01, 2013 at 10:41:27PM +0200, Rafael J. Wysocki wrote: > >> On Monday, April 01, 2013 03:11:09 PM Nathan Zimmer wrote: > >> > This eliminates the rest of the contention found in __cpufreq_cpu_get. > >> > I am not seeing a way to use the rcu so we will have to make due with a > >> > rwlock for now. > >> > > >> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > >> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > >> > Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> > >> > >> I've already applied this one. > >> > >> Can you please check if the version in my tree is OK? > >> > >> Rafael > >> > > > > Nope, the previous version was too different, probably best to just replace it. > > Nathan, > > First of all I should accept that I didn't had your last patch while > reviewing this > one earlier. Thanks Rafael. > > Now, I believe the previous patch which Rafael has pushed was good and we > can simply keep it. What you can do is, just add a patch over it (which would > mostly be 1/2 of your patchset), that simply separates rcu stuff out of the lock > and leave lock for cpufreq_data.. Yeah, I'd very much prefer that. Nathan, I'm going to keep the rwlock patch unless it is demonstrably incorrect. Thanks, Rafael
On Tue, Apr 02, 2013 at 02:48:07PM +0200, Rafael J. Wysocki wrote: > On Tuesday, April 02, 2013 10:34:21 AM Viresh Kumar wrote: > > On 2 April 2013 06:26, Nathan Zimmer <nzimmer@sgi.com> wrote: > > > On Mon, Apr 01, 2013 at 10:41:27PM +0200, Rafael J. Wysocki wrote: > > >> On Monday, April 01, 2013 03:11:09 PM Nathan Zimmer wrote: > > >> > This eliminates the rest of the contention found in __cpufreq_cpu_get. > > >> > I am not seeing a way to use the rcu so we will have to make due with a > > >> > rwlock for now. > > >> > > > >> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > > >> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > > >> > Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> > > >> > > >> I've already applied this one. > > >> > > >> Can you please check if the version in my tree is OK? > > >> > > >> Rafael > > >> > > > > > > Nope, the previous version was too different, probably best to just replace it. > > > > Nathan, > > > > First of all I should accept that I didn't had your last patch while > > reviewing this > > one earlier. Thanks Rafael. > > > > Now, I believe the previous patch which Rafael has pushed was good and we > > can simply keep it. What you can do is, just add a patch over it (which would > > mostly be 1/2 of your patchset), that simply separates rcu stuff out of the lock > > and leave lock for cpufreq_data.. > > Yeah, I'd very much prefer that. > > Nathan, I'm going to keep the rwlock patch unless it is demonstrably incorrect. > > Thanks, > Rafael > > > -- > I speak only for myself. > Rafael J. Wysocki, Intel Open Source Technology Center. Ok I'll go that route. -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 5139eab..7438c34 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -42,7 +42,7 @@ static struct cpufreq_driver __rcu *cpufreq_driver; static DEFINE_SPINLOCK(cpufreq_driver_lock); -static DEFINE_SPINLOCK(cpufreq_data_lock); +static DEFINE_RWLOCK(cpufreq_data_lock); static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); #ifdef CONFIG_HOTPLUG_CPU /* This one keeps track of the previously set governor of a removed CPU */ @@ -150,7 +150,7 @@ static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) goto err_out_unlock; /* get the CPU */ - spin_lock_irqsave(&cpufreq_data_lock, flags); + read_lock_irqsave(&cpufreq_data_lock, flags); data = per_cpu(cpufreq_cpu_data, cpu); if (!data) @@ -159,13 +159,13 @@ static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) if (!sysfs && !kobject_get(&data->kobj)) goto err_out_put_module; - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + read_unlock_irqrestore(&cpufreq_data_lock, flags); rcu_read_unlock(); return data; err_out_put_module: module_put(driver->owner); - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + read_unlock_irqrestore(&cpufreq_data_lock, flags); err_out_unlock: rcu_read_unlock(); err_out: @@ -276,9 +276,9 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) pr_debug("notification %u of frequency transition to %u kHz\n", state, freqs->new); - spin_lock_irqsave(&cpufreq_data_lock, flags); + read_lock_irqsave(&cpufreq_data_lock, flags); policy = per_cpu(cpufreq_cpu_data, freqs->cpu); - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + read_unlock_irqrestore(&cpufreq_data_lock, flags); switch (state) { @@ -802,12 +802,12 @@ static int cpufreq_add_dev_interface(unsigned int cpu, } rcu_read_unlock(); - spin_lock_irqsave(&cpufreq_data_lock, flags); + write_lock_irqsave(&cpufreq_data_lock, flags); for_each_cpu(j, policy->cpus) { per_cpu(cpufreq_cpu_data, j) = policy; per_cpu(cpufreq_policy_cpu, j) = policy->cpu; } - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + write_unlock_irqrestore(&cpufreq_data_lock, flags); ret = cpufreq_add_dev_symlink(cpu, policy); if (ret) @@ -858,12 +858,12 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, lock_policy_rwsem_write(sibling); - spin_lock_irqsave(&cpufreq_data_lock, flags); + write_lock_irqsave(&cpufreq_data_lock, flags); cpumask_set_cpu(cpu, policy->cpus); per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; per_cpu(cpufreq_cpu_data, cpu) = policy; - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + write_unlock_irqrestore(&cpufreq_data_lock, flags); unlock_policy_rwsem_write(sibling); @@ -918,15 +918,15 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) #ifdef CONFIG_HOTPLUG_CPU /* Check if this cpu was hot-unplugged earlier and has siblings */ - spin_lock_irqsave(&cpufreq_data_lock, flags); + read_lock_irqsave(&cpufreq_data_lock, flags); for_each_online_cpu(sibling) { struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + read_unlock_irqrestore(&cpufreq_data_lock, flags); return cpufreq_add_policy_cpu(cpu, sibling, dev); } } - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + read_unlock_irqrestore(&cpufreq_data_lock, flags); #endif #endif @@ -1006,10 +1006,10 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) return 0; err_out_unregister: - spin_lock_irqsave(&cpufreq_data_lock, flags); + write_lock_irqsave(&cpufreq_data_lock, flags); for_each_cpu(j, policy->cpus) per_cpu(cpufreq_cpu_data, j) = NULL; - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + write_unlock_irqrestore(&cpufreq_data_lock, flags); kobject_put(&policy->kobj); wait_for_completion(&policy->kobj_unregister); @@ -1067,12 +1067,12 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif pr_debug("%s: unregistering CPU %u\n", __func__, cpu); - spin_lock_irqsave(&cpufreq_data_lock, flags); + write_lock_irqsave(&cpufreq_data_lock, flags); data = per_cpu(cpufreq_cpu_data, cpu); per_cpu(cpufreq_cpu_data, cpu) = NULL; - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + write_unlock_irqrestore(&cpufreq_data_lock, flags); if (!data) { pr_debug("%s: No cpu_data found\n", __func__); @@ -1111,9 +1111,9 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif WARN_ON(lock_policy_rwsem_write(cpu)); cpumask_set_cpu(cpu, data->cpus); - spin_lock_irqsave(&cpufreq_data_lock, flags); + write_lock_irqsave(&cpufreq_data_lock, flags); per_cpu(cpufreq_cpu_data, cpu) = data; - spin_unlock_irqrestore(&cpufreq_data_lock, flags); + write_unlock_irqrestore(&cpufreq_data_lock, flags); unlock_policy_rwsem_write(cpu);
This eliminates the rest of the contention found in __cpufreq_cpu_get. I am not seeing a way to use the rcu so we will have to make due with a rwlock for now. Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> --- drivers/cpufreq/cpufreq.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-)